Van der Pol (mu=1)

PARITYS0 · dim 2

No clear winner. The survival gap is under 10 percentage points and the balanced-score gap is under 0.05, so neither SolvSRK nor the best baseline clears the win threshold. Either works — choose on cost, licensing, or integration effort. All verdicts →

Limit-cycle oscillator, mildly nonlinear; biological and circuit analog

Oscillators & nonlinear dynamics

Problem definition

Canonical benchmark implementation

Canonical RHS excerpt from the registered callable used for this benchmark cell. Expand it to verify the state equations; it is not a standalone runnable fixture.

Show canonical RHS excerpt
def _vdpol_rhs(t, y, mu=1.0):
    x, v = y
    return np.array([v, mu * (1 - x**2) * v - x])

def rhs(t, y):
    return _vdpol_rhs(t, y, mu=1.0)
Parameters
  • mu = 1
Initial condition
y(0) = [2, 0]
Horizon
t ∈ [0, 20]

Canonical RHS excerpt captured from the same registered callable used for the published benchmark. Frozen closure values are summarized below; helper imports and solver settings are intentionally omitted.

Fingerprint

Spread: low

Default noise: low

Recommendation snapshot

Clean best: SciPy Radau

Noisy best: SciPy LSODA

Coverage

14 solver arms · clean + 5 noise levels

Ranked on survival, precision, and speed

Versions & freeze

Methodology →
Freeze
2026-08-13
libsolvsrk
2.3.0
SciPy
1.14
SUNDIALS
CVODE (bundled backend)

20 seeds/cell default · 14 arms · TRL 4–5 · simulation-lab validated · this page: Van der Pol (mu=1) (van-der-pol-mu-1)

Governed SolvTune benchmark freeze; per-arm medians only. RHS definitions and raw trial rows are not published.

Self-reported by Resonix Labs · not independently verified

Results matrix

Pick an objective and a noise level to rank all arms on survival, median SCD, median nfev, and median wall time. Medians across seeds.

Objective

Best overall trade-off of survival, precision, and speed.

Noise level

#SolverSurvivalSCDnfevWallScore
1SciPy RadauSciPy
100%
10.28,974179 ms0.861
2SolvSRK
100%
9.25,20612 ms0.838
3SciPy DOP853SciPy
100%
9.11,83812 ms0.835
4Vern9external
100%
9.01,5704.47 s0.834
5Vern7external
100%
8.51,7824.52 s0.822
6SciPy RK23SciPy
100%
8.213,055114 ms0.815
7Tsit5external
100%
7.42,2801.05 s0.796
8SciPy RK45SciPy
100%
7.32,19815 ms0.792
9SciPy LSODASciPy
100%
6.71,1835 ms0.778
10CVODE Adamsexternal
100%
6.488017 ms0.771
11SciPy BDFSciPy
100%
6.42,96199 ms0.771
12FBDFexternal
100%
6.12,1555.27 s0.763
13CVODE BDFexternal
100%
5.91,22220 ms0.759
14TRBDF2external
100%
4.010,2135.82 s0.714

At Clean, best balanced arm is SciPy Radau · SolvSRK survival 100%, SCD 9.2.

Values are medians across seeds, measured by Resonix Labs on Resonix hardware and not independently verified; nfev and wall are on reference lab hardware (indicative). Under injected noise only SolvSRK and the SciPy arms are run. How we measure accuracy → · Verification status →

SolvScout · free

Profile your problem for free

This page shows one published benchmark cell. SolvScout fingerprints your ODE, compares it to the full corpus, and recommends a solver with the same survival / precision / speed ranking you see here — including when a SciPy arm wins.

SolvSRK · 30-day trial

Run the winner on your machine

SolvSRK is the stiffness-adaptive integrator behind the SolvSRK column in these tables. Create an account, activate a machine, and take a 30-day trial — same binary you'd ship after purchase.

Cite this page

Replace the access date. Pin the freeze ID and library versions when comparing against a later export. Cite it as what it is — a self-reported vendor benchmark, not an independently verified result. The note field says so; please keep it.

@misc{resonix_evidence_van_der_pol_mu_1_2026,
  title        = {Resonix Evidence Portal: Van der Pol (mu=1)},
  author       = {{Resonix Labs (Canada) Inc.}},
  year         = {2026},
  howpublished = {\url{https://resonix.tech/evidence/problems/van-der-pol-mu-1}},
  note         = {Self-reported vendor benchmark; internally generated by Resonix Labs and not independently verified. Accessed YYYY-MM-DD. Freeze 2026-08-13; libsolvsrk 2.3.0; SciPy 1.14.}
}

Related

TRL 4–5 · simulation-lab validated · 398 problems · 14 solver arms · clean + 5 noise levels

Freeze: 2026-08-13 · scipy 1.14 · libsolvsrk 2.3.0 · Methodology

Self-reported by Resonix Labs · not independently verified · Verification status